Polymerization products containing sulphur dioxide and process for producing the same



Patented Aug. 26, 1941 azssa'zs I ronmmmzsrros monuc'rs conrsmme SULPHUR DIOXIDE AND PROCESS FOR PRODUCING THE SAME Frederick E. Frey and 1mm 1). Snow, Battlesville, Okla., and Louis 11.

Fitch, Jr., deceased,

late of Bartlesville, OklaQ, by First National Bank or Bartlesville, administrator, Bartlesville, Okla...

assignors to Phillips Petroleum Company, Bartlesville, kla., a corporation of Delaware No Drawing. v Application September 6, 1938,

Serial No. 228,703

Claims.

This invention relates to the manufacture of new and useful products, generally of high molecular weight, or polymeric in nature, by causing sulfur dioxide to react with unsaturated compounds other than the olefin or conjugated diolefin hydrocarbons, and to processes by which such reactions can be made to take place.

A further object of the invention is to produce high molecular weight compounds containing sulfur dioxide and having incorporated in the molecule, radicals such as the hydroxyl or carboxyl, capable of undergoing further reaction with suitable chemical agents.

Other objects will appear as the inventionis more fully described.

Prior literature references to the reactions of S0: with unsaturated compounds are confined to the olefin and diolefin hydrocarbons. Mathews and Elder, British 11,635, 1914, claim the reaction of liquid $02 with oleflnic hydrocarbons, such as ethylene, propylene, and butylenes in sunlight of ultra-violet. light. De Bruin, Chem. Abs. 9,623 (1915) found that the conjugated diene, isoprene, when allowed to stand with liquid S02, forms a crystalline compound. Mathews and Strange, U. S. 1,196,259 (1916), react isoprene and other conjugated diolefins with S0: in the presence of halogen compounds such as HCl, iodine or acetyl chloride, which promote the formation of the crystallizable sulfoxide. Baclische Aniline and Sodafabrik, Ger. 236,386 (1911), Staudinger, Ger. 506,839 (1930), and Perkins, Canadian 329,043, (1933) ,-disclose the reaction of S0: with olefins having conjugated double bonds. Leopold Singer in French Patent 515,590 (1921) discloses a process for the production of lacquers, varnishes, etc., by reacting sulfurous acid with mineral oils. In these references to the prior -art. no mention is made of the reaction of S0:

with unsaturated compounds other than simple olefins and conjugated diolefins. Furthermore, since methods for the reaction of many of the simple olefinic hydrocarbons are still unknown, it does not necessarily follow from the previous disclosures that unsaturated compounds other than hydrocarbons would react with S02. We have found, however, that many compounds other than simple olefins and conjugated dioleiin hydrocarbons react with $02 to form high molecular weight polymers of a resinous nature.

We have reacted the following materials with sulfur dioxide:

The unsaturated halogen derivatives, vinyl chloride and allyl chloride react readily with liquid S02 in the presence of a catalyst or in light. The vinyl chloride forms a white solid which is insoluble in 30:, but which can be molded by heat and pressure. The allyl chloride forms a water white, glassy product somewhat soluble in S02. After molding by heat and pressure, the resin exhibits high mechanical strength. The unsaturated alcohol, allyl alcohol, reacts readily with S0: in the presence of catalyst or light. The solid resin obtained has a very high tensile strength.

The'unsaturated ether, allyl ethyl ether, reacts readily with S0: in the presence of catalyst or light. The'solid resinous product can be molded by heat and-pressure.

The olefin oxides, or oxide and propylene oxide react relatively more slowly with S0: in the presence of catalyst or light at temperatures at about 0 C. The productsare viscous fluids useful as softening agents, plasticizers, and solvents.

Esters of acrylic acid react readily with S0:

in the presence of light or catalyst to form products of desired properties. Ethyl arcylate reacts to form a soft, rubbery product soluble in, S0: and many organic solvents.

When S02 is passed into an unsaturated amine compound such as allylamine, the first energetic reaction is evidently between the NH: group and the S02. If after this reaction is complete, an excess of S0: is added and the mixture is exposed to light, a further reaction takes place, forming a compound of high molecular weight.

Diallyl, a diolefin not having conjugated double bonds and consequently not being capable of undergoing 1-4 addition of S01, was found to react rapidly with S0: to form a white insoluble difilcultly fusible solid.

The unsaturated aldehyde, acrolein, reacts slowly with S0: in the presence of light or catalyst. The reaction can best be carried out at temperatures below atmospheric. The product is a solid insoluble in $02.

The unsaturated acids, acrylic, allylacetic, and undecylenic react readily with S0: in the presence of a catalyst or light. The products are insoluble in the excess S02. They are softer than-.the products obtained from oleilnlc hydrocarbons of the same number of carbon atoms. the product of undecylenic acid being very soft andpliable.

The acetylene derivatives, ethyl acetylene and phenyl acetylene, react with S0: in the presence of light or a catalyst.

' The acetylene polymers, vinyl acetylene, di-

inner ethers', ethylene up to 40 C. but preferablyvinyl acetylene, and polydivinylacetylene, react slowly in liquid $02 in the light or in the presence of a catalyst to form aninsoluble brown solid.

The furane derivative, furfuryl alcohol, reacts with S02 in the light or in the presence of a catalyst. A Jet black solid material which is practically insoluble and can be molded only at high temperatures and pressures is formed.

Other compounds which we have converted to resins by reaction with $02 are: allyl cyanide, allyl isothiocyanate, allyl thiourea, and allyl urea.

Other materials which should react with S: are: crotonyl alcohol, chloroprene, bromoprene, unsaturated vegetable oilssuch as tung oil, and partially chlorinated oleflns such as the dicl loride of diallyl.

In most cases we have found that the treatment of the unsaturated product to remove any absorbed oxygen and oxidation products prior to reaction is desirable.

Although the reaction involves approximately equimolecular proportions of S02 and unsaturated compound, the reaction product usually removes excess S02 from the reaction phase in the adsorbed or dissolved form. It is, therefore, generally desirable to use more than the molecular equivalent of S02.

Any of the catalysts for these reactions previously discovered and disclosed can be used, in-

sofar as they are compatible with the unsaturated compound to be converted to resin.

' Resinous products formed from mixtures of simple oleflnic hydrocarbons and other unsaturated compounds appear to have properties which are generally intermediate between those formed from the individual constituents.

In many ways the production of resins from such compounds as unsaturated halogen derivatives, alcohols, ethers, esters, acid and aldehydes, or materials containing them, by reaction with S02 is highly desirable and advantageous. It

would permit the production of resins havingspecial properties; for example the allyl alcohol- S02 resin has unusually high tensile strength, while the undecylenic acid-S02 and ethyl acrylate-SOz resins are soft and rubbery. Then,-too, a resin in which is tiedup such a compound of multiple functions should be capable of further modification of properties by other chemical reactions after formation of the S02 complex. Apparently only the carbon to carbon double bond is involved in the resin reaction, leaving the other functional groups, such as hydroxyl or carboxyl, more or less free to undergo its characteristic reactions. Thus, an allyl alcohol resin or an acrylic acid resin might be esterifled in the usual manner with acid anhydrides or alcohols, respectively, to produce resins with a wide range of properties. Still another advantage of the use of these compounds is that they can be used to modify the properties of resins from unsaturated hydrocarbons and $02. This may be accomplished in either of two ways; the unsaturated polyfunctional compound may be mixed with the unsaturated hydrocarbon and S02 before reaction, in which case opportunity is afforded for molecules of both types of unsaturated compounds to build into the same resin molecule; or the resins of the two types of compounds may be formed by reacting separately with S02, and then be blended in the desired proportions after reaction.

We have produced useful resinous products by the reaction of S02 with unsaturated compounds other than simple olefinic hydrocarbons and conjugated dioleflnic hydrocarbons, have blended the resins so obtained with resins formed by the reaction of $02 with simple oleflns and/or dioleflns in order to modify the properties of the latter and have also mixed such unsaturated compounds with the simple olefins and dioleflns and reacted the mixture with S0: under the proper conditions.

The following examples will illustrate the process of the present invention:

I. Equal volumes of liquid S02 and allyl chloride are sealed in a glass tube and exposed to slinlight or artificial light, preferably of short wave length. After the reaction has gone to completion, as indicated by the conversion of/the fluid reactants to a stiff gel, the excess S02 is allowed to evaporate, leaving a white solid resin.

As a variation of the above, suitable for larger scale operation, the mixture of S02 and allyl chloride is placed in a bomb or autoclave provided with a suitable source of internal illumination and the reaction is promoted photochemically.

II. Equal volumes of liquid S0: and allyl alcohol are placed in a bomb or autoclave containing Dill-0.1 per cent of silver nitrate, or other suitable catalyst, and are allowed to react after thorough mixing. After the reaction has gone to completion, the excess S02 is allowed to escape and the solid resin is removed from the vessel.

III. To a mixture of 25 parts by weight of undecylenic acid and '75 parts of propylene was added somewhat more than twice its weight of liquid sulfur dioxide. After mixing, a catalyst solution consisting of 5% alcoholic lithium nitrate solution in ethyl alcohol was added at the rate of 2 per cent of the weight of the reaction mixture. The mixture was agitated while reaction was taking place. After completion of the reaction, the excess sulfur dioxide was removed. A resin having much better plasticity than that of propylene-sulfur dioxide resin was obtained. The product when molded also showed much less tendency to crack than the ordinary propylene sulfur dioxide resin.

IV. A mixture of 20 parts of propylene, 10 parts of methyl undecylenate and parts of sulfur dioxide was .caused to react in a pressure vessel by the addition of 2 parts of 5% alcoholic lithium nitrate solution. The mixture was agitated during reaction. At the end of the reaction the excess sulfur dioxide was expelled and there remained a resin having a higher solubility and elasticity than the product made from propylene a one.

We may also use other unsaturated acids and their esters such as acrylic, allylacetic, which will themselves react with sulfur dioxide in the absence of olefin hydrocarbons, in admixtures with olefin hydrocarbons. We prefer to use unsaturated acids or their esters in which the double bond is located at or near the end of the molecule opposite the carboxyl group and in which no branching of the hydrocarbon chain occurs at the double bond.

We claim:

1. The process of producing high molecular weight heteropolymeric products which comprises reacting sulfur dioxide with an unsaturated organic compound of the group consisting of esters of acrylic acid, acrylic acid, allylacetic acid and undecylenic acid.

2. The process of producing high molecular weight heteropolymeric products which compris- 8. The process of producing high molecular weight heteropolymers which comprises reacting sulfur dioxide with a mixture of simple olefins and ethyl acrylate.

9. The process of producing high molecular weight heteropolymers which comprises reacting sulfur dioxide with a mixture of simple oleflns and acrylic acid.

10. The process of producing high molecular 10 weight heteropolymeric products which comprissimple oleflns and unsaturated organic com- 15 pounds of the group consisting of esters of acrylic acid, acrylic acid, allylactic acid, and undecylenic acid.

7. The process of producing high molecular weight heteropolymers which comprises reacting sulfur dioxide with a mixture of simple oleflns and an ester of acrylic acid.

es reacting sulfur dioxide with a mixture of simple olefins and undecylenic acid.

FIRST NATIONAL BANK IN BARTLESVIILE, Administrator of the estate of Louis H. Fitch, Jr.

Deceased.

By J. F. CRONIN,

Vice-President.

FREDERICK E. FREY. ROBERT D. SNOW. 

